APPARATUS FOR DRIVING MICROMECHANICAL DEVICES
An interference modulator (Imod) incorporates anti-reflection coatings and/or micro-fabricated supplemental lighting sources. An efficient drive scheme is provided for matrix addressed arrays of IMods or other micromechanical devices. An improved color scheme provides greater flexibility. Electronic hardware can be field reconfigured to accommodate different display formats and/or application functions. An IMod's electromechanical behavior can be decoupled from its optical behavior. An improved actuation means is provided, some one of which may be hidden from view. An IMod or IMod array is fabricated and used in conjunction with a MEMS switch or switch array. An IMod can be used for optical switching and modulation. Some IMods incorporate 2-D and 3-D photonic structures. A variety of applications for the modulation of light are discussed. A MEMS manufacturing and packaging approach is provided based on a continuous web fed process. IMods can be used as test structures for the evaluation of residual stress in deposited materials.
1 . An apparatus for driving an electronic device comprising an array of microelectromechanical elements, said apparatus comprising:
an input to receive data; and
a driving circuit coupled to said input and configured to generate a select voltage and data voltages from said received data, and to apply said select voltage to one of rows or columns of said array and to apply a bias voltage to the rest of rows or columns of said array, and to apply said data voltages to the columns, in the case when said select voltage is applied to one of the rows, or to the rows, in the case when said select voltage is applied to one of the columns,
wherein each microelectromechanical element with said select voltage applied is actuated when the difference between the values of the data voltage and the select voltage applied to the element is above a first predetermined level, and is released when the difference between the values of the data voltage and the select voltage is below a second predetermined level, and wherein each element with the bias voltage applied maintain its state.
2 . The apparatus of claim 1 , wherein the bias voltage is within a hysteresis window of the device.
3 . The apparatus of claim 2 , wherein the bias voltage is in the middle of the hysteresis window.
4 . The apparatus of claim 1 , wherein said driving circuit further comprises:
a row driver circuit and a column driver circuit for addressing said device; and
a control circuit configured to send control signals to said row and column driver circuits to select the select voltage, the bias voltage and data voltages to be applied by said driver circuits to rows and columns of said device.
5 . The apparatus of claim 4 , wherein said row driver circuit is configured to apply one of a finite set of possible voltages to each row which is selected by said control signals, and said column driver circuit is configured to apply one of a finite set of voltages to each column which is selected by said control signals.
6 . The apparatus of claim 1 , wherein the data voltages comprise two possible values, the select voltages comprise two possible values such that the difference between one of the select voltages and one of the data voltages is above the first predetermined level, the difference between the other of the select voltages and one of the data voltages is below the second predetermined level, and the difference between the other of the select voltages and the other of the data voltages is below the second predetermined level.
7 . The apparatus of claim 6 , wherein the difference between the other of the select voltages and one of the data voltages is above the first predetermined threshold.
8 . The apparatus of claim 1 , wherein the select voltages are applied in alternating frames such that voltages of alternate polarity are applied to a selected row in successive frames.
9 . The apparatus of claim 1 , wherein the select voltages are applied in repetitive passes to at least portions of each one of successive frames.
10 . The apparatus of claim 1 , wherein the select voltages are applied to different portions of a frame at different rates.
11 . The apparatus of claim 1 , wherein the first predetermined threshold is about 9 volts and the second predetermined threshold is about 0 volts.
12 . The apparatus of claim 1 , wherein the select voltages are applied in frames, the select voltages being applied to successive rows in separate portions of each frame.
13 . An apparatus for driving an electronic device, said apparatus comprising:
a row driver circuit and a column driver circuit for addressing said device; and
a control circuit configured to send control signals to said row and column driver circuits to select a select voltage, a bias voltage and data voltages to be applied by said driver circuits to rows and columns of said device,
wherein data voltages are applied to the columns, in the case when said select voltage is applied to one of the rows and said bias voltage is applied to the rest rows, or to the rows, in the case when said select voltage is applied to one of the columns and said bias voltage is applied to the rest columns,
wherein actuation of each element with the select voltage applied occurs when the difference between the values of the data voltage and the select voltage applied to the element is above a first predetermined level, and release of the device occurs when the difference between the values of the data voltage and the select voltage is below a second predetermined level lowest, and
wherein each element with the bias voltage applied maintains its state.
14 . The apparatus of claim 13 , wherein said row driver circuit is configured to apply one of a finite set of possible voltages to each row which is selected by said control signals, and said column driver circuit is configured to apply one of a finite set of voltages to each column which is selected by said control signals.
15 . The apparatus of claim 13 , wherein the data voltages comprise two possible values, the select voltages comprise two possible values such that the difference between one of the select voltages and one of the data voltages is above the first predetermined level, the difference between the other of the select voltages and one of the data voltages is below the second predetermined level, and the difference between the other of the select voltages and the other of the data voltages is below the second predetermined level.
16 . The apparatus of claim 13 , wherein the select voltages are applied in frames, the select voltages being applied to successive rows in separate portions of each frame.
17 . An apparatus for driving an electronic device, said apparatus comprising:
means for receiving data; and
means for driving the electronic device, the driving means being coupled to the receiving means and configured to generate a select voltage and data voltages from said received data, and to apply said select voltage to one of rows or columns of said array and to apply a bias voltage to the rest of rows or columns of said array, and to apply said data voltages to the columns, in the case when said select voltage is applied to one of the rows, or to the rows, in the case when said select voltage is applied to one of the columns,
wherein each microelectromechanical element with said select voltage applied is actuated when the difference between the values of the data voltage and the select voltage applied to the element is above a first predetermined level, and is released when the difference between the values of the data voltage and the select voltage is below a second predetermined level, and wherein each element with the bias voltage applied maintain its state.
18 . The apparatus of claim 17 , wherein the driving means comprises a driving circuit.
19 . The apparatus of claim 17 , wherein the receiving means comprises an input to receive data.
20 . The apparatus of claim 17 , wherein the data voltages comprise two possible values, the select voltages comprise two possible values such that the difference between one of the select voltages and one of the data voltages is above the first predetermined level, the difference between the other of the select voltages and one of the data voltages is below the second predetermined level, and the difference between the other of the select voltages and the other of the data voltages is below the second predetermined level.